Question

1/m-n,2/n^2-m^2,3n/2(m+n)通分

Answer 1

1/(m-n)=-1/(n-m)

2/(n^2-m^2)=2/(n-m)(n+m)

3n/[2(m+n)]

公分母是2(m+n)(n-m)

通分后

1/(m-n)=-1/(n-m)=-2(m+n)/[2(m+n)(n-m)]

2/(n^2-m^2)=2/(n-m)(n+m)=4/[2(m+n)(n-m)]

3n/[2(m+n)]=3n(n-m)/[2(m+n)(n-m)]